Field of the Invention
This invention relates generally to a system and method for diagnosing faults when a vehicle push-button start system has failed and, more particularly, to a system and method for diagnosing faults when a vehicle push-button start system has failed, where the method includes monitoring the start sequence, identifying and recording fault information detected at key steps during the sequence, if any, and using the information during a no-start diagnosis.
Discussion of the Related Art
Some modern vehicles include a push-button engine start system where the vehicle operator will push a start/stop button inside of the vehicle to start the vehicle engine instead of the traditional rotating a key in a key ignition switch. When a vehicle operator pushes the start/stop button, various systems are activated in sequence in a controlled operation to ensure that the vehicle driver is authorized to start the vehicle and to perform various control and security steps for safety purposes and otherwise. One of the start conditions typically includes providing an automatic wireless communications with a fob carried by the vehicle operator that identifies the operator as an authorized user.
As with all vehicle systems, the push-button start system may fail when an authorized user pushes the start/stop button and the vehicle engine does not start. In response to such a start failure, the vehicle operator may take the vehicle to a service technician who will typically connect a diagnostic tool to the vehicle in an effort to identify the specific fault that is causing the start failure. Certain component faults and failures on a vehicle cause a diagnostic trouble code (DTC) to be issued that is stored in a vehicle controller and can be downloaded by the diagnostic tool to identify the fault associated with the DTC.
The current techniques for diagnosing a no-start failure in these types of vehicle push-button start systems does not link specific DTCs to the start sequence and control operation of the system. More specifically, DTCs are generally specific to a component on the vehicle, and may only identify certain types of faults, such as a short-to-ground or short-to-power failure, of the component. However, because the start sequence of a push-button start system is generally complex and involves a number of vehicle components and operations, it is often times difficult and time consuming to identifying a fault causing the start failure. For example, the push-button start system will look for a number of conditions that need to be satisfied in order for the vehicle engine to be started. Sometimes these conditions are not related to a specific component, and thus if the condition is not satisfied and there is no component failure, a DTC may not be issued. Hence, the service technician may connect the diagnostic tool to the vehicle and not be able to identify a specific fault by a DTC. In those cases, the service technician generally relies on experience and trial and error to replace and/or test different things on the vehicle to identify what is causing the no-start condition. Further, sometimes failures in the push-button start system are intermittent, where the vehicle engine may start sometimes and not start other times as a result of a loose wire or other type of failure on the vehicle, where the technician is required to identify the failure without the failure actually occurring at that particular time.